public Configurator() throws IOException {
    final File EXT_DIR = new File(System.getProperty("extensions", "ext"));

    EditorRegistry widgets = new EditorRegistry();
    XmlTestGroupReader reader = new XmlTestGroupReader();
    XmlTestGroupWriter writer = new XmlTestGroupWriter();
    AnnotationSchemaReader schema = new AnnotationSchemaReader();

    ClassEnumerator classes = new ClassEnumerator(EXT_DIR);

    classes.registerClasses(reader, writer, schema.TYPE_READERS, widgets);

    classes.registerClasses(schema);

    this.writer = writer;
    this.reader = reader;
    this.actions = schema.actions;

    form = new ConfiguratorForm(this, widgets, tests);
    form.addActions(actions);
    this.executor = new ExecutorForm(form.getRoot(), new Executor(classes.getClassLoader()));

    form.show();
  }